1. Field of the Invention.
The invention relates to the field of installations for providing closure or screening against the sun, and in particular to the field of slidably mounted curtains. Such curtains are generally fastened to a set of runners mounted to move along a rail, each of which runners is mounted on a pair of carrier wheels and is provided with a fastening element for fastening to the curtain. A carriage is driven along the rail via a belt or via a cord under the action of manual operation, or under the action of an electro-mechanical actuator. The carriage moving causes the various runners to move, either via the curtain itself, or via cords connecting the first runner to the carriage and each runner to the next runner. When the curtains are in a plurality of panels closing towards each other, each panel of curtain is driven by a carriage. The carriage also makes it possible to form a coupling between the two ends of the belt, which belt thus forms an endless drive element between two drive pulleys.
2. Brief Description of the Related Art
Motor-driven curtains are in common use in hotel rooms or in conference centers, i.e. in places very often designed by architects seeking to achieve aesthetically pleasing appearance. In particular, the curtains are mounted across openings that themselves are not plane and/or that follow curves for reasons of making the place look aesthetically pleasing.
The problems involved in providing carriages for curtains that are to follow curved rails have been known for a long time. In particular, document GB-A-735 305 describes a hinged carriage that is adapted to travel around the curves in the rail. That carriage is made of a flexible strip on which plates equipped with vertical and horizontal wheels are mounted. That carriage is thus capable of rolling along a V-shaped rail on a plurality of wheels, while also accommodating distortions in a plane perpendicular to its longitudinal axis, for traveling around the curves in the rail. In addition, that curtain is mounted on simple runners with a single pair of wheels on a common axis perpendicular to the rail for each runner.
Alternatively to being mounted on a flexible strip, the various subassemblies of the carriage may be articulated via hinges. Document GB-A-735 305 does not give any additional details on that construction.
Document JP-A-04 079916 describes a motor-drive system of the linear type in which a curtain drive carriage is also made up of a plurality of subassemblies articulated via hinges.
Such hinged carriages are particularly advantageous for use on curved rails. Unfortunately, they can lack rigidity for traveling along rectilinear portions of the rail, which can cause considerable amounts of friction if the carriage folds or twists when such folding or twisting is not necessary. In addition, the state of the art does not make any provision to adapt the carriage as a function of the configuration of the rail or of the length and of the tension of its drive belt.